Edward Tufte in the book The Visual Display of Quantitative Information states, more or less, that ink is expensive. Any ink which is not used to actually convey information is chartjunk and it will only detract from conveying information. When looking at displays of data (say charts and the like) this is abundantly obvious.
I would guess that the same applies to user interfaces -- I can think of a lot of what Apple has done as more or less following it, but I was wondering if there is a generalized principal which can be said of UI design.
Does such a principle exist? How would it be stated in the UI context?